Why Word's native HTML export is a disaster
Open a Word doc, File → Save As → Web Page (.htm). The output is 50KB+ for a one-page document, full of <o:p>, <w:WordDocument>, mso-* CSS classes, conditional comments for IE6, and inline styles on every paragraph. Modern browsers render it but search engines hate it, CMSs choke on it, and any developer tasked with cleaning it up will quote you a day of work. mdisbetter strips all of that and outputs the document as standard HTML5 with semantic tags.
What you get
Clean semantic HTML5: <h1> through <h6> for headings, <p> for paragraphs, <ul>/<ol>/<li> for lists, <table>/<tr>/<td> for tables, <strong>/<em> for inline formatting, <a> for hyperlinks. No inline styles. No proprietary namespaces. No MSO comments. Just HTML you can drop into any CMS or web page and style with your own CSS.
For AI input, Markdown beats HTML
If the goal is feeding the document to ChatGPT, Claude, or Gemini, HTML is verbose — <h2>Section</h2> wastes tokens compared to Markdown's ## Section. Word to Markdown produces the same structural fidelity at roughly 30-40% fewer tokens, which directly cuts API costs.